1. Technical Field
The present invention is directed toward clutch brakes and more particularly toward clutch brakes for automotive vehicles.
2. Background Art
The clutch brake is typically utilized to slow down or stop the transmission input shaft from rotating when the clutch assembly is disengaged. The function is to aid in shifting the transmission into a reverse or forward gear, including upshifting and downshifting. A clutch brake is generally coupled to the transmission input shaft and disposed in a confined area between the release-bearing mechanism and an adjacent transmission. When the clutch pedal is selectively depressed or the release-bearing mechanism is forced toward the transmission, the front and rear faces of the brake are clamped to resist rotation. As the brake resists rotation, the rotational speed of the input shaft decreases, thereby allowing a smooth gear engagement.
Various clutch brakes designs have been utilized in the past. Each of these designs, however, has attendant disadvantages associated with the fabrication, assembly and installation, or maintenance of the brake once installed.
Early clutch brakes were formed as unitary annular metallic assemblies. Because these brakes were formed as unitary assemblies, this type of clutch brake could be replaced only by partially displacing the clutch or transmission so as to free one end of the shaft upon which the clutch brake was mounted. Once free, the clutch brake could be slid off and replaced. Thus, maintenance or replacement of the brake was a time consuming and costly procedure.
More recently, clutch brakes have been formed as two mating halves which are assembled and secured about the shaft. Two such split clutch brakes are shown in U.S. Pat. No. 4,512,450 to Daniel A. Babcock and U.S. Pat. No. 5,031,739 to Richard A. Flotow et al.
U.S. Pat. No. 4,512,450 to Babcock discloses a clutch brake comprising a pair of initially separate semi-annular sections having radial interlocking teeth, which permit the clutch brake to be assembled as it is installed on the driven shaft. The halves are placed along the periphery of the shaft with the tangs located in keyways along the shaft. The halves are then assembled by engaging the interlocking teeth, and then spot welding the components together. Alternately, roll pins are assembled into one half of the clutch brake and then are pressed into mating holes in the other half of the clutch brake to secure the components together.
U.S. Pat. No. 5,031,739 to Flotow, et al. discloses a clutch brake formed from a pair of identically shaped semi-annular sections. Each section has circumferentially extending protrusions located at either end, an outer protrusion at one end of the section and an inner protrusion at the other end of the section. Each outer protrusion has a radial clearance hole, and each inner protrusion has a radial threaded hole. In assembly, the sections are placed independently over the shaft. Threaded fasteners are inserted radially into the clearance holes and threaded into the threaded holes to secure the components together. The fasteners form the tangs for securing the brake to the shaft.
Each of these multi-component clutch brakes require extensive on-site assembly, as the separate components are assembled together as they are placed over the shaft, and/or once they are assembled over the shaft. This on-site assembly is generally cumbersome in that the assembler must reach through an approximately 5 inch by 8 inch inspection portion of the bell housing of the transmission in order to secure two fasteners along opposite sides of the shaft. Further, loose components, such as roll pins and threaded fasteners may be easily lost during the "blind" installation. These loose parts can damage the transmission if left loose in the transmission housing.
Additionally, special installation tools are often required to perform the assembly. Such tools may be unavailable on a remote repair site. Further, such dedicated tools may present significant expense. For example, welding equipment is quite expensive, and may not be readily available or portable.
The present invention is directed to overcoming one or more of the problems discussed above.